Coil for artificial-refrigerating systems



Feb. 19, 1929.

H. L. FOSTER con. Fon ARTIFICIAL REFRIGERATING SYSTEMS Filed June 25,1925 gn/@antan Alm/1rd l. fils/er.

Patented Feb. 19,1929.-

UNITED STATES HOWARD L. FOSTER, OF DETROIT; MICHIGAN.

COIL FOR ABTIFICIAL-REFIRIGERATING lSYSM'JEJNIE.

Application led June 25, 1925. Serial No. 39,457.

. '10 to hold the cold and retard the'increase of temperature within therefrigerator. Another object of the invention is to provide a coilembedded in a block of aluminum rovidcd with a series of ribs or finsexten ing from the body of the aluminum to increase the eicienc ofthecoil in radiatingor absorbing heat. further object of the invention isto provide a three sided cooling coil which is embedded in aluminum andmay be laced 20 in a refrigerator with the open side of t e coil towardthe door thusallowing the use of the space within the coil for storingfood 'and' saving considerable space in the refrigerator. Another objectof the invention is to provide' in'a refrigerating system a coppercooling coil which is embedded in aluminum which being a betterconductor of heat than copper absorbs 'the heat, from the refrigerantand transmits'the same to the refrigerant in the copper coil thusincreasing theeliciency of vthe coil in the cooling of the interior ofthe refrigerator. 'I'hese objects and the several novel features of theinventionnre hereinafter more fully described and claimed and thepreferred form of construction by which these objects are attained isshown in the accompanying drawings in which-f Fig. 1 is a plan view of acoill embodying my invention positioned within a refriger ator.

Fig. iis a section taken on line Q-Qof Fig. 1. Y

Fig. 3 is a perspective view ofthe copper coil before being embedded inthe aluminum.

The coil 1 is made up as shown in Fig. 3 so that it is open on one sideand is provided with an inlet end 2 and-an outlet end 3 shown in Figs.1, 2 and 3. 'This coil is placed in a vmold which is then filled withmolten alu. minum so that the coil isembedded in the aluminum..and themold is shaped to form ribs or fins 4 on the aluminum. The inlet end ofvthe coil 2 is turned up so that it extends upwardly between twoof thens 4 andfdoes not extend into the chamber 5 with- Cil in the coil. Theoutlet end 3 is also turned up in the same manner and extends between.two of the fins 4 so that it is also out of the way and does'not extendinto the chamber 5. As will be seen in the drawing the coil is, formedso that one side is left open. The coil in'tliis shape is particularlydesigned to be placed within the ice compartment 6 of a refrigeratorsothat by openin the door 7 of the refrigerator access may be had to theoschamber 5 formed by the three sides of the coil. With this arrangementthe coil does not take up an entire compartment of the refrigerator andany artlcles which must be kept verycold may be placed in the chamber 5.This peculiar form of refrigerating coil however is used only in thesmall refrigerating systems such as household vrefri erators or thelike. Where the coil is use in larger refrigeratfing systems it may bemade of the usual cylindrical shape and the aluminum vcast thereaboutand provided with the fins 4.

When the coil is used in a small household refrigerating system thesystem is usually arranged to operate in cycles. As the 'mterior oftherefrigerator increases in temperatureto a certain point therefrigerant is circulated through the low pressure coil and decreasesthe temperature of the low pressure coil and the aluminum. When thetemperature Within the refrigerator decreases to a certain pointthecirculation of the refrigerant is automatically stopped until thetemperature again increases to a certain point. During this cycle as thetemperature increases the aluminum defrosts due toits ability to absorband conduct the heat of the atmosphere and for this reason the frostdoes not build up on the aluminum and tend to form an insulating wallwhich is the case in most artificial refrigerating systems in which thefrost continues to build up on the cooling coil to such an extentthat`the coldness of the coil is not communicatedto the atmosphere ofthe refrigerator. In the household 100 type of artificial refrigerator'the aluminum defrosts during each cycle and correspondingly increasesthe eiiiciency of the coil in cooling the refrigerator. When an ordinarycopper coil is used there is very little volume 105 of metal and due tothis reason the coils are easily affected by changing temperatures inthe refrigerator but by embedding the coils in ,aluminum the body pfmetal is increased to such extent that it "will maintain the in- 11oterior of the box at a low temperature for av about the copper tubingand 'havinga series 40 much longer period-than the when used alone andthe body of metal thus acts to some extent like a cake of ic'e placedfin the boX.-

While I have described the coil as used on the low ressure or coolingcoils of an artificial reiiigeratingsystem, 'the same principle may beused on the high pressure or warm coils of the system as thev aluminumhas the characteristic of. eiiciently radiating wall lining'the coolingchamber andhavi11g 5o and absorbing heat which is assisted by providingthe fins' on the aluminum. lVhen used on the high pressure coil theshape of the coil is immaterial and also when used on the cooling coilof an artificial refrigerating system ofv larger capacity than thehousehold type the common cylindrical coil may be used and embedded inaluminum 'with the fins extend- .ing either 'radially orcircumferentially, the

three sided coil being particularly designed to line the interior of theice chambenof the usual .household refrigerator and allow easy accessthereto through the refrigerator door.y

From the foregoing description it becomes evident that the device isvery simple and eiicient in operation, of order, and will conduct orradiate heat with an increasedeliciency as compared with the usual coiland provides a devicewhich accomplishes the objects described.

. Having thus fully described my invention, its utility and mode ofoperation, what claim and desire to secure by Letters Patent of the Unid States is-. 'e v 1. A coil or an artificial refrigerating systemcomprising a copper tube bent to the desired shape, and an aluminum bodycast will not easily get out copper coils iof fins may be easily andcheaply madeM projecting'from the surfaces thereof.

2. Acoil for an artificial refrigerating system comprising a copper tubebent to form a three sided coil, a three sided aluminum body cast aboutthe copper tubing and a series of fins projecting from the surfaces ofthe aluminum.

3. In an artificial refrigerating system, a cooling chamber, a threesided aluminum ribbed surfaces, and a cooling coil embedded in thealuminum wall.

4. In an, artificial refrigeratingsystem, a cooling chamber providedwith a door opening thereinto,l an aluminum lining' for the chamberhaving an open side toward the door, a series of fins extending from thesurface of the aluminum lining and a cooling coil\embedded in thealuminum lining.

5. In artificial refrigerating apparatus having a circulating systemthrough which t-he refrigerant may be intermittently circulated, thecombination therewith of a heat insulated compartment, a coil of theapparatus being located in the. said compartment, a metal body withinwhich the coil is embedded and the Nolume of which is in excess\of thevolume of metalforming the coil, said metal body providing a means bywhich the heat is extracted from thev compartment and due to its avidityfor heat, maintaining the temperature of the compartment practicallyvcon- I stant between intervals of circulation of the refrigerant. J

In testimony whereof, I sign this specification.

HOWARD L. FOSTER,

